I don't understand how any of this works.

It's probably easier just to look at the equations rather than talk about it... When you have 2x+7, when x is 1, the answer is 9. When x goes up to 2, the answer is 11. 11 is more than 9, so as the value of x increases, the value of the expression also increases. But when the expression is something like 10-x, when x is 1, the answer is 9. When x is 2, the answer is 8. 8 is less than 9. So as the value of x increases, the value of the expression decreases in this case. Hope that helps.

I don't understand because when I was doing the math above one day I did that same kind of math and I picked increase and it was wrong then I picked decrease and it was wrong then I picked it stays the same and it was wrong I didn't understand why it didn't tell me which one was right.

It was probably a mistake in the coding. I didn't have a problem with it. Try it again and see if it works!

Can any of you guys can help me with this? I am really struggling with this topic. Please help...

What part of it do you not understand? If it's all of it, you should probably go to previous lessons, and study a bit more. If there's a particular section you don't understand, or a part where it gets confusing, then we can better help you.

why does it decrease if your added k + 35 as k decreases?

Remember "death to the world?" and also it is because you are adding less to 35. Ex. if k = 5 k+35=40, but if k decreases (4) 35+4=39, so it decreased by 1.

Why does it stay the same? It would decrease because it's a division problem. How does it stay the same?

2t divided by t is the same as 2 - the t on top and bottom can 'cancel' each other out (as they'll grow at the same rate). It's a tricky one and will become more apparent as you go further through the Algebra syllabus here!

whats 93 times x if x is 63?

So you don't have to do it yourself (just because you seem to be struggling) the answer is 5,859

I don't understand why: What happens to the value of the expression 2t/t as t increases? And the answer is: It stays the same. How is that possible? I don't get it.

Pay attention to the numerator for example if t = 3, 2*3/3 =2. Another example if t = 634, 2*634/634 =2.

Main content

MAP Recommended Practice

Course: MAP Recommended Practice > Unit 17

Lesson 14: Expression value intuition

Expression value intuition

Google Classroom

In an expression like 2x+7, the value of x can change. As the variable increases and decreases, what happens to the value of the expression?

Khan Academy video wrapper

Expression value intuitionSee video transcript

Make sure you understand the question that Sal solved.

What happens to the value of the expression $100 - x$ ‍ as $x$ ‍ increases?

Let's try some practice problems!

Question 1

What happens to the value of the expression $k + 35$ ‍ as $k$ ‍ decreases?

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michaeline knower
Posted 6 years ago. Direct link to michaeline knower's post “I don't understand how an...”
I don't understand how any of this works.
Button navigates to signup pageComment on michaeline knower's post “I don't understand how an...”
(15 votes)
Answer
- Avia
  Posted 6 years ago. Direct link to Avia's post “It's probably easier just...”
  It's probably easier just to look at the equations rather than talk about it...
  When you have 2x+7, when x is 1, the answer is 9. When x goes up to 2, the answer is 11. 11 is more than 9, so as the value of x increases, the value of the expression also increases.
  But when the expression is something like 10-x, when x is 1, the answer is 9. When x is 2, the answer is 8. 8 is less than 9. So as the value of x increases, the value of the expression decreases in this case.
  Hope that helps.
  Comment on Avia's post “It's probably easier just...”
  (39 votes)
http://facebookid.khanacademy.org/100000173937440
Posted 8 years ago. Direct link to http://facebookid.khanacademy.org/100000173937440's post “there seems to be many qu...”
there seems to be many quetions on this topic. let me clear up all your confusions. just fill in the problems above with a number like 1 and do it than fill it again with a number higher. if the answer u get is lower than the other one it decreases and if it is higher than it increases and if it is the same it is the last choice. i hope this helped u all. bye bye and feel free to ask any questions to me. i will gladly try to answer them. got it guys and girls
Button navigates to signup pageComment on http://facebookid.khanacademy.org/100000173937440's post “there seems to be many qu...”
(15 votes)
Answer
krivera2.2015
Posted 8 years ago. Direct link to krivera2.2015's post “I don't understand becau...”
I don't understand because when I was doing the math above one day I did that same kind of math and I picked increase and it was wrong then I picked decrease and it was wrong then I picked it stays the same and it was wrong I didn't understand why it didn't tell me which one was right.
Button navigates to signup pageComment on krivera2.2015's post “I don't understand becau...”
(11 votes)
Answer
- Darkknight Infinitive
  Posted 3 years ago. Direct link to Darkknight Infinitive's post “It was probably a mistake...”
  It was probably a mistake in the coding. I didn't have a problem with it. Try it again and see if it works!
  Comment on Darkknight Infinitive's post “It was probably a mistake...”
  (3 votes)
drobe
Posted 7 months ago. Direct link to drobe's post “I don't get why 2t over t...”
I don't get why 2t over t as t increases stays the same, why? I just don't get it.
Button navigates to signup pageComment on drobe's post “I don't get why 2t over t...”
(11 votes)
Answer
- danae.apel
  Posted 5 months ago. Direct link to danae.apel's post “I don't get it either”
  I don't get it either
  Button navigates to signup page
  (5 votes)
Chrisean Williams
Posted 6 years ago. Direct link to Chrisean Williams's post “Can any of you guys can h...”
Can any of you guys can help me with this? I am really struggling with this topic. Please help...
Button navigates to signup pageButton navigates to signup page
(10 votes)
Answer
- Mageborn
  Posted 6 years ago. Direct link to Mageborn's post “What part of it do you no...”
  What part of it do you not understand? If it's all of it, you should probably go to previous lessons, and study a bit more. If there's a particular section you don't understand, or a part where it gets confusing, then we can better help you.
  Comment on Mageborn's post “What part of it do you no...”
  (3 votes)
ergenbrightfarris
Posted 7 months ago. Direct link to ergenbrightfarris's post “why does it decrease if y...”
why does it decrease if your added k + 35 as k decreases?
Button navigates to signup pageComment on ergenbrightfarris's post “why does it decrease if y...”
(6 votes)
Answer
- alexande.j.demare
  Posted 7 months ago. Direct link to alexande.j.demare's post “Remember "death to the wo...”
  Remember "death to the world?" and also it is because you are adding less to 35. Ex. if k = 5 k+35=40, but if k decreases (4) 35+4=39, so it decreased by 1.
  Button navigates to signup page
  (10 votes)
gc515226
Posted 7 years ago. Direct link to gc515226's post “Why does it stay the same...”
Why does it stay the same? It would decrease because it's a division problem. How does it stay the same?
Button navigates to signup pageButton navigates to signup page
(5 votes)
Answer
- Matthew Brener
  Posted 6 years ago. Direct link to Matthew Brener's post “2t divided by t is the sa...”
  2t divided by t is the same as 2 - the t on top and bottom can 'cancel' each other out (as they'll grow at the same rate).
  
  It's a tricky one and will become more apparent as you go further through the Algebra syllabus here!
  Button navigates to signup page
  (6 votes)
𒆜ᛔ𝙚חʝꭵ𒆜
Posted 4 months ago. Direct link to 𒆜ᛔ𝙚חʝꭵ𒆜's post “im so banboozled”
im so banboozled
Button navigates to signup pageComment on 𒆜ᛔ𝙚חʝꭵ𒆜's post “im so banboozled”
(7 votes)
Answer
aroutzahn
Posted 8 months ago. Direct link to aroutzahn's post “whats 93 times x if x is ...”
whats 93 times x if x is 63?
Button navigates to signup pageComment on aroutzahn's post “whats 93 times x if x is ...”
(3 votes)
Answer
- alexande.j.demare
  Posted 7 months ago. Direct link to alexande.j.demare's post “So you don't have to do i...”
  So you don't have to do it yourself (just because you seem to be struggling) the answer is 5,859
  Button navigates to signup page
  (2 votes)
Shalini Sajith
Posted 8 months ago. Direct link to Shalini Sajith's post “I don't understand why: W...”
I don't understand why: What happens to the value of the expression 2t/t as t increases? And the answer is: It stays the same. How is that possible? I don't get it.
Button navigates to signup pageButton navigates to signup page
(3 votes)
Answer
- Poonam.Renu
  Posted 4 months ago. Direct link to Poonam.Renu's post “Pay attention to the nume...”
  Pay attention to the numerator for example if t = 3,
  2*3/3 =2. Another example if t = 634, 2*634/634 =2.
  Button navigates to signup page
  (2 votes)